Automatic sprinkler.



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WILBERFORCE BEECHER HAMMOND, OF BOSTON, ltIASSACI-IU'SETTS, ASSIGNOR, BY MESNE ASSIGNMENTS, TO COMBINED HEAT AND SPBINKLER CUMPANY, A G0213.-

PORATTON OF MASSACHUSETTS.

nuroiue'rrc SPRINKLER.

Specification of Letters Patent.

Patented July it?, i917..

Application inea January as, 1915. serial No. 4,934.

To all whom 'it may concern:

Be it known that I, WiLnEnroRon Bitner-IER l-lAi/ijifronn, a citizen of the United States,

and resident of Boston, in the county of Suffolk and State of Massachusetts, have invented new and useful lmprovements in Automatic Sprinklers, of which the following is a specification.

My invention relates to automaticv sprinklers for protection against fire, and has for its object the production of a sprinkler head which may be immediately secured to a hot water pipe but nevertheless maintain by reason of its principles of construction the sensitive fusible member at a safely low temperature,V so that, although. the sprinkler head itself is intimately secured toa circulation pipe which may contain water at a temperature as high as 230o F. or even higher, theheat sensitive fusible member which is a characteristic of all commercially acceptable sprinkler heads, will nevertheless remain at a temperature far below that at which it is designed to soften and release the sprinkler in case of accidental fire. Y

My improvements are adapted and applicable to that type of sprinkler (of which there are several examples in use) in which the valve which closes the sprinkler aperture is held in closed position by means of bars or levers Linder a bending strain. According to the particulars of construction of the example of such type of sprinkler head which may be selected, there may be one or more of such bar or: lever members under bending strain. For illustration of my invention I have taken two examples of sprinklers of the type above designated, and it willrbe perceived from the following description that my invention is applicable to any sprinkler of this type.

ln the drawings hereto annexed,- Figure l shows a sprinkler head of the above designated type known commercially as the Evans sprinkler, modified, however,

Vby the application thereto of my invention;

Fig. 2 shows a sprinkler head of the commercially known Walworth type, similarly altered and qualified by the addition of my invention; and

Fig. 3 shows, in section, a modified form of the leverarm of the type of sprinkler illustrated in Fig. l.

Referring to Fig. 1, which lllustrates my invention as applied to a sprinkler of the Evans type (see U. S. Patent No. 729,306) The sprinkler head S is attached to a pipe connection R which in the case proposed forms the part of a hot water circulating system. The valve V of the sprinkler is held firmly pressed to its seat under normal conditions by means of the toggle members T', T2, which are held in position by means of lever arms, which in the illustration shown are constructed according to my invention. These lever arms as heretofore embodied in sprinklers of the Evans type and shown in said Patent No. 729,306 are simply integral metal extensions from the toggle members T', T2, themselves, and these extensions are held under bending strain by means of a fusible link F which serves as a tie between the two arms. In the standard Evans sprinkler, however, these two arms are relatively quite large bodies of metal highly conductive of heat, so that if, as is usually the case, the fusible link F is of such composition that it will 'soften and let go its hold upon the arm when raised to a temperature of about 160 F., and such a sprinkler head bers T', T2, I mount thereon slender rods L, L2, preferably of .steel, or it may be of a high quality of bronze, and inclose these rods with a stout sleeve of insulating material, such as for instance, asbestos wood. These sleeves l, lf2, are perforated so that they fit over the slender rods L, L2. By means of nuts N', N2, and W', W2, at the inner and outer ends of rods L, L2, respectively, T then set the composite lever arms tightly against the toggle members T', T2, respectively. The outer ends of the sleeves I', l2, of heat insulating material, enter the holes F', F2, in the link F in the usual manner. The link F comprises some readily fusible material, and performs the oflice of sulating sleeve I2, while the tension pro-v Vthe heat-'sensitive member which in emergency releases the sprinkler.

The bending strain placed upon these composite vlever arms produces a condition of compression in the lower side of the insulating sleeve If and the upper side of the inducedin the rods L, L2, initially, by means ofV theV nuts il', W, NNVZ, and finally by the strut action of the insulating sleeves assists the sleeves of insulating material I',

124siig'st'aining theY tensile stress on their outer sides, which otherwise such insulating material would be ill-qualified to endure. For the most part, however, the high capacityefy such material for resisting compressive strains is'depended on to sustain the va- Y cross section of these members.

riousparts of thevalve-holding system in their proper relation. New it.' will be observed thatthe only channels for the ready conduction of heat frointhetoggle members T, T2, to the fusiblelinkF, are the slender metal rods L, L2,

through whicha negligible quantity of heat can be transmitted on account of the small Y It will be observed, also, that the heat conductive members of'this system need not and in the instance shown do not make any contact with the fusible'link F which is, on the contrary, in contact withy the heat-insulating members metal/members L, L2, though large enough. to'v supply all the tensile strength necessary,are toosmall to transmit heat to any materialextent, whereas the members 17.25,71?, which Yprovide the compressive strength necessary to resist bending quite ycontipletely resist the transmission of heat through their substance. As thus constructed the'sprinkler vof the type designated is of amplestrength to maintain its normal condition ofvalve closure, but is nevertheless so highly resistant to the transmission of heat that the fusible member is unaffected by heat conducted through the pipe VR even though the temperature therein be very high.

Ay modified v,form of compressible lever arm is vshown in section in Fig. 3. Here the otherY exampleslof sprinkler heads of thev same general type, Ihave shownin Fig. 2

av sprinklerof `another type commercially knownas theY Walworth (see U. S. VFatent No. 467,970), in which'fthe valve V is held toits seat. by 'means of Va bell-crank lever vpivoted at P, the shorter arm A of the lever bearing upon the top of the valve, and the longer arm being tied to the top of the sprinkler attachment by means of a fusible link T. As heretofore constructed the longer upwardly extending arm of the bell-crank lever in the Walworth structure is made of metal sufficiently stout to sustain the bending strain incident to holding the valve V to its seat, and is therefore a member admirably adapted to transmit heat by conduction to the fusible link T.

My invention as applied to the Walworth sprinkler may be carried out as follows: The upwardly extending metal portion of the bell-crank lever at A is made of reduced cross section, a cross section preferably so small that no appreciable amount of heat will be Vconducted through it. A seat A2 is formed at the base of the slender arm A and over this arm there is placed a sleeve of heat-insulating material B, this being held tightly in place and under compression by means of a nut M at the upper end of the rod or slender extension A. The fusible link T bears on the heat-insulating sleeve B and ties the composite lever arm to the upper projection O of the sprinkler. It will not be necessary further to describe this application of my invention since it will be obvious that the same conditions inhere therein as characterize the form of my invention shown in Fig. 1. The type of sprinkler illustrated in Fig. 2 does not lend itself sol readily to the application of my invention as that shown in Fig. l, since one of the conductive paths for heat (from the valve V to the upper projection O) remains substantially the same as in the commercially known Walworth sprinkler; the provision of the slender arm A and heat insulating strut B removes one of the heat conductive paths previously existing in this type, and to that extent reduces the liability of the fusible member T to unintended fusion, should such a sprinkler be associated with a hot water pipe.

Generally speaking, my invention is characterized by the employment of insulating material, in a sprinkler structure of the type designated, which intervenes between the sensitive fusible link and metallic parts of the sprinkler through which heat may be transmitted by conduction from the pipeon which the sprinkler is mounted, so that the fusible link or equivalent sensitive member is indifferent to heat conditions inside the'water-containing system, while exposed freely to heat conditions ,outside the said water-containing system.

' More specifically, my invention is characterized yby the application to that type of sprinkler in which the valve is held in its seat by means of bending strain applied to a lever or (bar, of a composite arm composed partly of material of high tensile strength, such as metal, and partly of material of loW tensile strength, but of high compressive strength and high heat insulating properties and utilizing the tensile strength of the former (as a tie) and the compressive strength of the latter (as a strut) to sustain the bending strain necessary to hold the sprinkler valve in its normal closed position, and by thus minimizing the amount of heat which can be conducted from the parts of the sprinkler head in immediate juxtaposition to the valve to the fusible retaining member which normally holds the bar or lever member under bending strain to keep the valve closed.

I claim:

1. In an automatic sprinkler of the type designated, the combination With a retaining piece comprising readily fusible material, of valve-restraining means comprising an arm held under bending strain by said retaining piece, said arm comprising a tension-member of metal and a Vstrut member of heat insulating material.

2. In an automatic sprinkler of the type designated, the combination With a retaining piece comprising readily fusible material, of valve-restraining means comprising an arm held under bending strain by said retaining piece, said arm comprising a tension-member of metal and a strut member of heat insulating material, the retaining piece being in contact With the strut member.

3. In an automatic sprinkler of the type designated, the combination With a retaining piece comprising readily fusible material, of valve-restraining means comprising an arm held under bending strain by said retaining piece, said arm comprising a relatively slender metallic tension member and a sleeve of heat insulating material surrounding said tension member and constituting a strut member.

4. In an automatic sprinkler of the type designated, the combination with a retaining piece comprising readily fusible material, of valve-restraining-means comprising an arm held under bending strain by said retaining piece, said arm comprising a relatively slender metallic tension member and a sleeve of heat insulating material surrounding said tension member and constituting a strut member, the retaining piece being in contact With the said insulating sleeve.

Signed by me at Boston, Massachusetts, this 20th day of January, 1915.

WILBERFORCE BEECHER HAMMOMI).

Witnesses:

ROBERT CUSHMAN, RICHARD W. HALL.

Copies othis patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, I). G. 

